0=x^2+7x-64

Solution for 0=x^2+7x-64 equation:

0=x^2+7x-64

We move all terms to the left:

0-(x^2+7x-64)=0

We add all the numbers together, and all the variables

-(x^2+7x-64)=0

We get rid of parentheses

-x^2-7x+64=0

We add all the numbers together, and all the variables

-1x^2-7x+64=0

a = -1; b = -7; c = +64;
Δ = b2-4ac
Δ = -72-4·(-1)·64
Δ = 305
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-\sqrt{305}}{2*-1}=\frac{7-\sqrt{305}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{305}}{2*-1}=\frac{7+\sqrt{305}}{-2}
$